921540 has 24 divisors (see below), whose sum is σ = 2580480. Its totient is φ = 245728.

The previous prime is 921523. The next prime is 921563. The reversal of 921540 is 45129.

921540 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 921540.

It is an unprimeable number.

921540 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7620 + ... + 7739.

It is an arithmetic number, because the mean of its divisors is an integer number (107520).

2⁹²¹⁵⁴⁰ is an apocalyptic number.

It is an amenable number.

921540 is an abundant number, since it is smaller than the sum of its proper divisors (1658940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

921540 is a wasteful number, since it uses less digits than its factorization.

921540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15371 (or 15369 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 921540 is about 959.9687494914. The cubic root of 921540 is about 97.3131200076.

Adding to 921540 its reverse (45129), we get a palindrome (966669).

The spelling of 921540 in words is "nine hundred twenty-one thousand, five hundred forty".